Those are not really underrated or underground these days though, they are some of the mainstays of clubs in Berlin.

I don't think even Golden Gate nor ://about:blank would be considered truly "underground" anymore. As usual with the underground stuff you need to dig deeper to find them, as I don't live in Berlin I need to rely on my local friends to take me to these places as they are inserted within the underground culture.

Those are probably all listed in Lonely Planet at this point. Renate and Butkze had stints as scene clubs, but that was like 15 years ago when they were illegal. Sisphyos still has some scene-y-ness, but is a mix of tourists and locals. It only managed to stay off the radar for a couple years when it was only an outdoor location. But it's so big that it can absorb the crowds better. Birgit, on the other hand, was purpose-built for tourists. I actually like going to the biergarten there since it's right around the corner from where I live, and have played there a couple times, but it's unabashadly a club built to look like Berlin clubs except be more accessible for tourists. There was never a point that it was a scene spot.